wireshark: Drop glib dependency
    
    The only function that we currently use from glib is g_sprintf().
    That's a very big gun for such small target. Not only that, but
    we've silently relied on wireshark dragging in the glib. Replace
    the g_sprintf() with plain sprinf() so that we can drop the glib
    dependency.
    
    Signed-off-by: Michal Privoznik <mprivozn@redhat.com>